What restrictions exist when working with SQL and what should be considered when designing databases?

When working with SQL and designing databases, it is important to consider the following constraints and points:

• Data normalization: helps avoid redundancy and anomalies during updates, but excessive normalization can complicate queries.
• Integrity constraints: primary keys, foreign keys, and unique constraints ensure data correctness.
• Performance: indexes speed up searches but slow down inserts and updates.
• Data types: choosing the right types affects storage and processing efficiency.
• Transactions and locking: ensure data consistency but can lead to deadlocks and reduced parallelism.
• Scalability: SQL databases are better suited for structured data and complex queries but may face challenges with horizontal scaling.